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Updated: Jun 7, 2026
A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.
Published on: November 7, 2018
[Rapid detection of Shigella dysenteriae by PCR assay]
Hongyuan Chen1, Qingping Zhong, Li Wang
1The Higher Education Key Lab of Guangdong Province Food Quality and Safety, Institute of Food Quality and Safety, South China Agricultural University, Guangzhou 510642, China.
Abstract:
Based on the invasive plasmid antigen H gene (ipaH) of S. dysenteriae, one pair of specific primers was designed for PCR assays in this study. The concentrations of dNTP, Mg2+ and primer, dosage of Taq DNA polymerase, annealing temperature and circulating parameter in the PCR amplification system were optimized. In this way, a rapid and stable method of PCR assay for the detection of S. dysenteriae was established. The specificity and sensitivity of PCR were also analyzed. The detection limits of pure culture and genomic DNA in the PCR assay were 1.06 x 10(2) cfu/ml and 106.34 pg/PCR system, respectively. The detection limit for S. dysenteriae in artificially contaminated food samples was 3.21 x 10(4) cfu/ml. These results indicated that the PCR method for S. dysenteriae detection was simple, rapid, high in specificity and sensitivity and suitable for the detection of pathogens in foods caused by Shigella dysenteriae.
Insights
A new PCR assay targets the ipaH gene for rapid Shigella dysenteriae detection. This method is highly specific and sensitive, suitable for identifying this pathogen in food samples.
Area of Science:
- Microbiology
- Molecular Biology
- Food Safety
Background:
- Shigella dysenteriae is a significant cause of dysentery.
- Accurate and rapid detection methods are crucial for food safety and public health.
- Existing detection methods may lack specificity or speed.
Purpose of the Study:
- To develop and optimize a Polymerase Chain Reaction (PCR) assay for the specific detection of Shigella dysenteriae.
- To evaluate the sensitivity and specificity of the developed PCR method.
- To assess the applicability of the PCR assay for detecting S. dysenteriae in food matrices.
Main Methods:
- Design of specific primers targeting the invasive plasmid antigen H (ipaH) gene of S. dysenteriae.
- Optimization of PCR reaction parameters including dNTPs, Mg2+, primer concentration, Taq DNA polymerase dosage, annealing temperature, and cycling parameters.
- Analysis of PCR specificity and sensitivity using pure cultures, genomic DNA, and artificially contaminated food samples.
Main Results:
- A rapid and stable PCR assay for S. dysenteriae detection was successfully established.
- The detection limit was 1.06 x 10(2) CFU/ml for pure culture and 106.34 pg/PCR system for genomic DNA.
- The assay detected S. dysenteriae in artificially contaminated food samples at a level of 3.21 x 10(4) CFU/ml.
Conclusions:
- The developed PCR method offers a simple, rapid, highly specific, and sensitive approach for S. dysenteriae detection.
- This PCR assay is suitable for identifying Shigella dysenteriae as a pathogen in food samples.
- The findings contribute to improved food safety surveillance and control of shigellosis outbreaks.
